Relax requirements on android_ycbcr to allow P010

The existing comments on android_ycbcr only allowed for formats
with 8 bit channels. The P010 format has 10 bits of data packed
into 16 bit channels with 6 unused bits.

Bug: b/216638710
Test: none, just comment change
Change-Id: I57d5825a87f0c3dbf4a47b3f88ac1f9e65ad97fe